A tubular installation system includes a J-lay tower structure for lowering and raising a tubular or an accessory along a firing line; a tubulars supply system; an accessory supply system; and a loader system configured for transporting a tubular and an accessory between the horizontal tubular supply position and the firing line, wherein the loader system comprises: a loader device with a base and a boom which is pivotable with respect to the base between a lowered position for gripping a tubular and an accessory in the horizontal accessory supply position, and a raised position for delivering then to the firing line; a line-up tool, wherein the line-up tool is configured to exchange a tubular and an accessory with the loader device and transport a tubular between the loader device and the firing line.